Longtime Pacifica City Councilmember Mary Ann Nihart has been forced by a legal technicality to cancel her re-election campaign, potentially leading to a shakeup on the council that would shift the balance of power to preservationists who oppose developers, but support rent control.

Nihart’s troubles stem from the Hatch Act, a federal law prohibiting members of the U.S. government’s executive branch from participating in partisan elections. A psychiatric nurse by trade, Nihart holds a management position with the Department of Veterans Affairs, and is therefore considered a member of the executive branch.

Currently serving her second term on the City Council, Nihart did not run afoul of the Hatch Act in previous elections, because council races in San Mateo County are not generally considered partisan.

That changed this year, when the San Mateo County Democratic Central Committee endorsed another candidate in the election, Deirdre Martin. The U.S. Office of Special Counsel then received anonymous complaints claiming Nihart’s campaign constituted a Hatch Act violation.

After investigating, the Office of Special Counsel told Nihart she would need to cease all campaigning in order to keep her job. In an Oct. 28 news release, Nihart announced she was withdrawing her candidacy.

Nihart’s name remains on the ballot, however, and some have speculated the popular incumbent might be re-elected despite having withdrawn.

If Nihart won re-election, the City Council could then hold a special election, or choose an appointee to fill Nihart’s seat until the next council election in 2018. This has led to speculation that the council might appoint Nihart, a possibility she rejected.

“I am out of the race, and can in no way influence the race,” Nihart said. “I have closed my campaign, dissolved my campaign committee, and told them to stop campaigning for me.”

The current makeup of Pacifica’s council has not been advantageous to the town’s preservationists or tenant-rights activists. Mayor Sue Digre and Councilmember John Keener have usually sided with those contingents, but have been outvoted by the other council members on some issues, such as rent control.

Mayor Pro Tem Mike O’Neill and Councilmember Karen Ervin have sometimes favored economic growth over attempts to block new developments, and both have voted against rent control.

Nihart is a moderate known for making thoughtful decisions about key issues, but has voted with O’Neill and Ervin often enough to arouse the ire of preservationists and tenant advocates.

Two council seats are up for grabs this year — Nihart’s, and that of Councilmember Karen Ervin, who chose not to run for re-election.

Nihart’s withdrawal leaves three candidates vying for those two seats. Candidates Deirdre Martin and Bridget Duffy are both in the preservationist camp, and strongly support rent control.

The third candidate, Sue Vaterlaus, is a Realtor who opposes rent control. Some of her detractors claim she might support the kinds of new construction projects that are unpopular with the town’s preservationists.

But Vaterlaus said some developments, such as a proposed new library and the Beach Boulevard and Palmetto Streetscape projects (all of which would revitalize the Sharp Park neighborhood’s commercial district) are crucial to Pacifica’s economic and cultural viability.

Pacifica misses out on revenues when people drive through on their way to shop and dine in Half Moon Bay, Vaterlaus said, adding she would like to give those day-trippers a reason to stop in town.

“I don’t think people come here to shop, and I think there are people who don’t want people to come here to shop,” Vaterlaus noted.

Martin, meanwhile, has been derided by critics, who claim she would “vote no on everything,” and obstruct development projects.

Martin disagreed with that assessment. “I fully support rebuilding Beach Boulevard and protecting all our homes and infrastructure [from sea-level rise],” she said.

By her own admission, Duffy has raised almost no campaign money, and is therefore not considered a viable candidate. But Martin said Nihart’s withdrawal might have increased Duffy’s viability, adding many of her own supporters also support Duffy.

If a recent informal social media poll is any indication, the most probable outcome is that both Vaterlaus and Martin will be elected. And Martin, Digre, and Keener would likely outvote Vaterlaus and O’Neill on various issues.

“If Deirdre and I both get elected, I think it’s going to be a challenge for the next two years,” Vaterlaus acknowledged.

O’Neill said regardless of who is elected, he will work to find consensus with his fellow council members, because the new council will be faced with numerous crucial issues.

Among those is a prevalence of vacant storefronts in the town’s shopping centers. O’Neill said he will ask the council to consider a vacancy ordinance, which would fine commercial landlords who leave storefronts vacant for too long.

Duffy might be the race’s underdog, but she said she hopes to be among the two winners, because realtors and developers hold too much sway over Pacifica’s politics.

“Our government has been placating the developer-real estate industry rather than helping people,” Duffy claimed.